The equation of line a is y=1/2x−1, and it passes through point (6,2). Line b is perpendicular to line a, and it passes through point (−6,2).

Question

A: What is the slope of line b?

B: What is the y-intercept of line b?

Select two answers: one for A and one for B.

Responses:

1. B: 1
2. B: -10
3. A: 2
4. B: -1
5. A: -1/2
6. A: −2
7. B: 5
8. A: 12

Answer 1

The equation of line a is y=1/2x−1, and it passes through point (6,2). Line b is perpendicular to line a, and it passes through point (−6,2).

A: What is the slope of line b?

B: What is the y-intercept of line b?

slope of line a = 1/2

slope (m) of line b = -2/1 = -2 (negative reciprocal)

One point on line b = (-6, 2)

x = -6 y = 2

Substitute in equation & solve for b (y-intercept)

y = mx + b

2 = -2(-6) + b

2 = 12 + b subtract 12 from both sides

-10 = b

y-intercept of line b = -10

point (0, -10)

Answer 2

slope of line b is -1/2, the negative inverse of 2

line b's equation is

y-2 = (-1/2)(x+6)

y =-x/2 -3+2

y =-x/2 -1, -1 is the y intercept of line b